Police officers on the beat in London could end 200 years of tradition by swapping their dark blue uniforms for high visibility yellow jackets.

Metropolitan Police bosses believe the fluorescent, waterproof jackets will make it easier for the public to spot officers who are patrolling on the streets.

A trial of the new “high-viz” uniform is taking place in three London boroughs and Londoners were asked their opinion of the change in a two week survey on Facebook and Twitter.

The Met said the results were still being examined but comments on Facebook showed a mixed response to the plan.

One said the high-viz jackets would only make the police look like other officials such as traffic wardens or security guards. Others said the black uniforms were smarter and more traditional.

Others said they preferred yellow because it made it easier to see officers.

High viz jackets are currently worn routinely by officers attending traffic accidents or those on motorcycles or on bicycles though many patrol officers also use them. They are also worn by officers on duty at riots and protests.

The move comes as the Met is expected to approve plans to change the design of its response cars from the traditional “jam sandwich” colours to the “battenburg” design favoured by provincial forces.

The changes to the jacket design could cost as much as £10 million according to insiders, at a time when the force is trying to find savings of £500 million.

Critics say the moves are aimed at making it appear there are more police officers on the streets as numbers are being cut.

Glen Smyth, a former chairman of the Metropolitan Police Federation, said : “Hi-viz jackets are part of a smoke and mirrors trick to make it look like there are more police officers than there actually are.

"Police officers are supposed to stand out by looking smart. That won’t be the case when they are all wearing yellow."

John Tully, the Met Fed’s current chairman, said: “ I like the ceremonial image of the London police officer. But we have to realists as well and realise times have moved on and we have to be operationally match-fit, and part of that is being properly dressed.”

A Met spokesman said : “The force is proposing to introduce new high-viz yellow jackets to police uniform in a bid to improve visibility.

“The public were asked their opinion on the jackets, compared to the existing black jackets, via Twitter and Facebook over a two-week period. A trial of the jackets took place in December 2012 in Hackney, Hammersmith & Fulham and Sutton. Feedback is currently being collated via a user survey.

“A decision on whether the jackets should be rolled out across London will be made following the results from the trials and the social media vote.

“The assessment of the results is ongoing.

As a decision is yet to be made in relation to whether a new high-viz jacket will be adopted, we are not in a position to speculate about costs at this stage.”